System and method for voice control of medical devices

ABSTRACT

A light source includes a wavelength shifter that is capable of shifting a shorter optical signal wavelength to a longer optical signal wavelength based at least in part on a Raman effect in a waveguide. The wavelength shifter includes a pump laser that operable to produce the shorter optical signal wavelength. The wavelength shifter also includes an intermediate stage that is coupled to the pump laser and capable of producing an intermediate optical signal wavelength. The intermediate optical signal wavelength is longer than the shorter optical signal wavelength. The wavelength shifter further includes a final stage capable of generating the longer optical signal wavelength. The final stage includes at least in part a ZBLAN waveguide and wherein the longer optical signal wavelength is greater than 1.7 microns and is greater than the intermediate pump signal wavelength.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/652,276 entitled “System and Method for Voice Control of MedicalDevices” filed Aug. 29, 2003. Application Ser. No. 10/652,276 claims thebenefit under 35 U.S.C. §119(e) to U.S. Provisional Patent ApplicationNo. 60/408,025 entitled “Voice Control of Medical Instruments andDevices” filed Sep. 3, 2002.

TECHNICAL FIELD OF INVENTION

This invention relates generally to medical devices and moreparticularly to a system and method for voice control of medicaldevices.

OVERVIEW

Medical procedures typically use medical instruments or devices thattend to require a high level of manual dexterity on the part of medicalprofessionals. To achieve this high level of dexterity, medicalprofessionals require years of training and practice. This high level ofdexterity and the strain imposed on the medical professional when usingthose instruments can cause the medical professional to become fatiguedduring medical procedures. For example, certain medical instrumentsrequire the medical professional to use both hands and to stand next tothe patient, sometimes in an awkward position through the entireprocedure. This can create fatigue, thereby limiting the number ofprocedures that the medical professional is able to perform in a givenperiod. In addition, the high level of fatigue may lead to unnecessaryand dangerous errors occurring during medical procedures.

SUMMARY OF EXAMPLE EMBODIMENTS

In one embodiment, a medical device comprises an insertable portioncapable of being inserted into an orifice associated with a body of apatient. The insertable portion comprising an automated head unitcapable of being manipulated in at least two axes of motion based atleast in part on one or more control signals. The medical device furthercomprises one or more controllers coupled to the automated head unit. Inone particular embodiment, the one or more controllers generate the oneor more control signals based at least in part on an input signal.

In another embodiment, a medical device capable of minimizing tissuedamage comprises an insertable portion capable of being inserted into anorifice associated with a body of a patient. The medical device furthercomprises one or more sensors coupled to the insertable portion. The oneor more sensors capable of generating a feedback signal capable of beingused to substantially minimize damage to tissue associated with thepatient.

In yet another embodiment, a medical device capable of being used in amedical procedure comprises a pump laser capable of generating a pumpsignal. The medical device further comprises a Raman wavelength shiftercoupled to the pump laser, at least a portion of the wavelength shiftercomprising a waveguide structure. In one particular embodiment, theRaman wavelength shifter generates an output optical signal comprising awavelength of approximately 1.7 microns or more.

In still another embodiment, a medical device capable of being used in amedical procedure comprises a Raman wavelength shifter operable togenerate an optical signal comprising a mid-infrared wavelength. Atleast a portion of the Raman wavelength shifter comprises a chalcogenidewaveguide.

In another embodiment, a system for controlling a medical deviceincludes a monitor capable of communicating medical informationassociated with a patient and a communication device capable ofreceiving one or more input signals from a user. In one particularembodiment, the one or more input signals are based at least in part onthe medical information displayed on the monitor. The system furtherincludes one or more processors coupled to the communicated device andoperable to convert the one or more input signals into one or morecontrol signals capable of being used to manipulate a medical device.

Depending on the specific features implemented, particular embodimentsmay exhibit some, none, or all of the following technical advantages.Various embodiments may be capable of reducing medical professionalfatigue through the implementation of a control system capable ofmanipulating a medical device through voice commands. Some embodimentsmay be capable of controlling a medical device from a remote location.Other embodiments may be capable of reducing the level of dexterityrequired of a medical professional when performing a medical procedure.

Other technical advantages will be readily apparent to one skilled inthe art from the following figures, description, and claims. Moreover,while specific advantages have been enumerated, various embodiments mayinclude all, some, or none of the enumerated advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the present invention andcertain features and advantages, thereof, reference is made to thefollowing description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 illustrates one example embodiment of a medical device controlsystem;

FIG. 2 illustrates another example embodiment of a medical devicecontrol system;

FIG. 3 illustrates an example medical device capable of being insertedinto a patient's body during a medical procedure;

FIG. 4 is a block diagram illustrating a flow of command signals from amedical professional to a medical device in a medical device controlsystem;

FIG. 5 is a flow chart illustrating an exemplary method for processing avoice control signal and/or a command signal received by a medicaldevice control system;

FIG. 6A compares a surgical incision made using a 2.94 micron opticalsignal wavelength to a surgical incision made using a 6.45 micronoptical signal wavelength;

FIG. 6B illustrates example evanescent spectra in different cell-typeregions;

FIG. 7 illustrates example attenuation characteristics of severaloptical fibers based on wavelength;

FIGS. 8A through 8D are block diagrams illustrating example embodimentsof Raman wavelength shifters and/or Raman oscillators capable ofshifting a pump signal to an output signal wavelength of 1.7 microns ormore; and

FIGS. 9A through 9C are block diagrams illustrating example embodimentsof pump sources that are capable of generating a pump signal for use ina Raman wavelength shifter.

DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 illustrates one example embodiment of a medical device controlsystem 100. In this example, system 100 includes a medical device 10, amanipulator 40, a microphone 50, a display device 60, and a host 70. Invarious embodiments, system 100 may be capable of receiving voicecommands associated with the manipulation of medical device 10 from amedical professional, such as a nurse, a medical assistant, a medicaltechnician, and/or a doctor. In some cases, system 100 is capable ofassisting a medical professional during a medical procedure byprocessing data signals associated with one or more voice commands andmanipulating medical device 10 in response to those commands.

Medical device 10 may comprise any device or instrument that a medicalprofessional needs to perform a medical procedure. Medical device 10 cancomprise, for example, a surgical scalpel, a scope, a laser, an imagingdevice, a microscope, or a combination of these or any other suitabledevice. As used throughout this document, the term “scope” refers to anymedical device capable of entering a patient's body, such as endoscopes,colonoscopes, gastroscopes, enteroscopes, bronchoscopes, laryngoscopes,choledochoscopes, sigmoidoscopes, duodenoscopes, arthoroscopes,cystoscopes, hyteroscopes, laparoscopes, or a combination of these orany other suitable device.

In one particular embodiment, medical device 10 comprises an endoscope.In those cases, the endoscope may comprise an insertable portion capableof being inserted through an orifice associated with a patient. In otherembodiments, the insertable portion may be capable of being guidedthrough the patient's orifice, and capable of collecting biologicalsamples from the patient for investigation. The orifice associated withthe patient may comprise, for example, a throat, a mouth, a nasalpassage, an orifice created by the medical professional, and/or anyother suitable orifice. In some embodiments, medical device 10 mayinclude a fiber-optic cable with a lens system at the end that iscapable of sending images to a camera and/or a display device, such asdisplay device 60.

In other embodiments, medical device 10 may comprise one or more sensorscoupled to feedback control circuitry that is capable of minimizingcollateral tissue damage during a medical procedure. In variousembodiments, the one or more sensors and the control circuitry may becapable of providing positioning information to a medical professionaland/or a controller, such as system controller 90. In other embodiments,the one or more sensors and the control circuitry may be capable ofproviding data associated with one or more physiological parametersassociated with the patent to a medical professional and/or acontroller. In some cases, the one or more sensors may be capable ofdetecting and/or alerting a medical professional or a controller whenmedical device 10 is in close proximity to and/or in contact withtissue. In other cases, the one or more sensors and the controlcircuitry may be capable of detecting when medical device 10 is incontact with tissue and capable of overriding control signals receivedby medical device 10.

In this example, manipulator 40 includes an actuation unit 20 and asupporting structure 30. Actuation unit 20 may house one or more controlsystems capable of receiving control signals and manipulating medicaldevice 10 in response to those control signals. The one or more controlsystems may comprise, for example, a mechanical control system, anelectrical control system, or a combination of these or any othercontrol system. As used throughout this document, the phrase “mechanicalcontrol system” refers to a control system that at least partiallyincludes mechanical components. In various embodiments, actuation unit20 can implement a mechanical control system, such as a hydraulicsystem, pneumatic system, or a pulley guide-wire system.

Supporting structure 30 may comprise a robotic arm, one or more pivotedlinks, multiple links connected together to move is a “scissor-like”manner, or any other structure capable of supporting and manipulatingmedical device 10. Although this example depicts manipulator 40 andmedical device 10 as separate devices, manipulator 40 and medical device10 can comprise a unitary medical apparatus capable of performing thedesired functionalities without departing from the scope of the presentdisclosure. For example, manipulator 40 and medical device 10 can becombined to form a unitary medical apparatus, such as an endoscope, havea automated portion.

In some embodiments, a freedom of motion associated with manipulator 40can have a resolution that substantially replicates the manual dexterityof a medical professional and/or a manual medical device used by themedical professional. In some cases, manipulator 40 may have a step sizeand/or angle of rotation step size that is substantially similar to themanual dexterity of a medical professional and/or a manual medicaldevice used by the medical professional. For example, the number ofdegrees of manipulation freedom associated with medical device 10 canmatch the number of degrees of manipulation freedom currently availableon manual devices. That is, if a conventional manual device that hasfour degrees of freedom in the x-y plane, then the range of motionassociated with manipulator 40 can include at least four degrees offreedom in the x-y plane. In some embodiments, manipulator 40 mayinclude manual override controls that allow a medical professional toexercise manual control of medical device 10.

Manipulator 40 is coupled to host 70 through a first communication link45. As used throughout this document, the term “couple” and or “coupled”refers to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. In this example, first communication link 45 is operable tofacilitate the communication of command/data signals 47 betweenmanipulator 40 and host 70. Command/data signals 47 may comprise, forexample, video signals from a video device coupled to medical device 10,data obtained by sensors coupled to medical device 10, or manipulationcommands generated in response to voice commands, auxiliary inputcommands, and/or automated commands.

In this example, host 70 is capable of performing a desiredcommunicating and/or computing functionality. For example, host 70 maybe capable of at least partially contributing to the manipulation ofmedical device 10. In other embodiments, host 70 may be capable ofcollecting, entering, processing, storing, retrieving, amending, and/ordispatching medical data during a medical procedure. In operation, host70 may execute with any of the well-known MS-DOS, PC-DOS, OS-2, MAC-OS,WINDOWS™, UNIX, or other appropriate operating systems. In someembodiments, host 70 may include a graphical user interface (GUI) 72that enables a medical professional to display medical data and/ormedical video associated with medical device 10. Host 70 may comprise,for example, a desktop computer, a laptop computer, a server computer, apersonal digital assistant, and/or any other computing or communicatingdevice or combination of devices.

In this example, host 70 includes system controller 90 capable ofprocessing, collecting, storing, retrieving, and/or amending medicaldata and/or video during a medical procedure. System controller 90 maycomprise one or more computers, an embedded microprocessor, or any otherappropriate device or combination of devices capable of processingand/or generating voice command signals 47 and/or 57. In operation,system controller 90 may execute with any of the well-known MS-DOS,PC-DOS, OS-2, MAC-OS, WINDOWS™, UNIX, or other appropriate operatingsystems. In this embodiment, system controller 90 may implement voicerecognition software operable to process voice command signals 57. Forexample, system controller 90 may implement one or more voicerecognition software programs, such as ViaVoice or Dragon SpeechRecognition software, or any appropriate proprietary or non-proprietaryvoice recognition software. In certain embodiments, the voicerecognition software may be programmed to recognize the medicalprofessional's voice and commands may be customized to the medicalprofessional's preferences. In addition, the voice recognition softwaremay be capable of filtering out background noise.

System controller 90 is operable to process voice command signals 57,generate command/data signals 47 in response to the voice command, andcommunicate the command/data signals 47 to manipulator 40. Systemcontroller 90 may also be used to collect and record data using a memorystorage device. System controller 90 may be operable to provide dataassociated with a patient's medical status during a medical procedure tothe medical professional using display device 60 and/or GUI 72, or anyother appropriate devices.

In this embodiment, host 70 also includes an auxiliary input device 80coupled to system controller 90. Although a keyboard is depicted in thisexample, any other device capable of inputting commands and/or data maybe used without departing from the scope of this disclosure. In thisexample, auxiliary device 80 is operable to facilitate manual entry ofmanipulation commands to supplement and/or replace voice commands. Inaddition, the medical professional may use auxiliary device 80 to inputdata into system controller 90, such as the patient's physiologicalparameters, for example, blood pressure, heart rate, blood oxygen level,or to retrieve data stored in a memory device associated with host 70.

In this example, system 100 also includes display device 60 and agraphical user interface (GIU) 72, each capable of displaying medicalinformation, such as medical data and/or medical video. Display device60 and GUI 72 may comprise, for example, a monitor, a LED, a heads-updisplay, virtual reality goggles, a closed-circuit television, a CAVEenvironment, or any other device or combination of devices capable ofdisplaying. In some cases, display device 60 and GUI 72 may display alive video image from a video device associated with medical device 10,information about a patient's medical status, such as the current stateof any number of the patient's physiological parameters, informationabout the particular medical device 10 being used, or any otherinformation that may assist a medical professional during a medicalprocedure. In this example, display device 60 is coupled to host 70through a third communication link 65, which is operable to facilitatethe communication of data signals 67 to and/or from host 70.

In this example, system 100 also includes communication device 50 thatenables a medical professional to communicate with host 70.Communication device 50 can comprise any device that enables a medicalprofessional to communicate with host 70. Communication device 50 maycomprise, for example, a telephone, a wireless device, a voice-over-IPdevice, a unidirectional microphone attached to a headset worn by amedical professional, a bi-directional microphone, or any other suitablecommunicating device or combination of devices. Communication device 50may be selectively attached to and/or placed near the medicalprofessional for ease of use. Attaching communication device 50 to themedical professional can, in some cases, advantageously minimizebackground noise. Although system 100 includes one communication device50 in this example, any other number of communication devices may beused without departing from the scope of the present disclosure.Communication device 50 is coupled to host 70 through a secondcommunication link 55, which is operable to facilitate the communicationof voice command signals 57 between communication device 50 and host 70.

In the illustrated embodiment, system 100 includes at least a firstcommunications link 45 a second communications link 55, and a thirdcommunications link 65 each operable to facilitate the communication ofdata to and/or from host 70. Communications links 45, 55, and 65 mayinclude any hardware, software, firmware, or combination thereof. Invarious embodiments, communications link 45, 55, and 65 may comprise anycommunications medium capable of assisting in the communication ofanalog and/or digital signals. Communications links 45, 55, and 65 may,for example, comprise a twisted-pair copper telephone line, a fiberoptic line, a Digital Subscriber Line (DSL), a wireless link, a USB bus,a PCI bus, an Ethernet interface, or any other suitable interfaceoperable to assist in the communication of information to and/or fromnetwork 104.

In conventional medical procedures involving a scope, a medicalprofessional manually manipulates the medical device based on feedbackfrom the medical device. The medical professional typically uses onehand to hold the medical device and guide it into and through apatient's body. The medical professional's other hand is used tomanipulate the manual controls of the medical device. Thus, conventionalsystems typically require significant manual dexterity, which can resultin a significant amount of strain on the medical professional.

Unlike conventional procedures, system 100 comprises a communicationdevice 50 that enables a medical professional to manipulate medicaldevice 10 using voice commands, auxiliary input commands, and/orautomated commands. Allowing a medical professional to use voicecommands and/or automated commands can significantly reduce the manualdexterity, and the resulting strain, imposed on the medical professionalduring a medical procedure.

In operation, a medical professional can speak voice commands intocommunication device 50 for communication to host 70. Host 70 receivesvoice command signals 57 from communication device 50 and processesthose signals using a voice recognition module associated with host 70.Host 70 converts the voice command signals into command/data signals 47and communicates signals 47 to manipulator 40. Manipulator 40 respondsby causing medical device 10 to perform its desired function. Voicecommands may comprise, for example, a voice to take a photograph of aportion of the patient's body, a voice command to change an image sizeby zooming in or out, or any other suitable voice command capable ofcausing medical device 10 to perform its functionality. In otherembodiments, host 70 is capable of automatically generating command/datasignals 47 based at least in part on data received from medical device10 through communication link 47.

FIG. 2 illustrates another example embodiment of a medical devicecontrol system 300. System 300 includes system 150 for remotemanipulation of a medical device 210 and system 200 for voice control ofmedical device 210. In this example, system 150 is capable ofcontrolling at least a portion of system 200 from a remote location. Forexample, a medical professional may use system 150 to remotely controlsystem 200 in the case where the medical professional is not locatednear system 200. The remote location may comprise, for example, adifferent location in the hospital that includes system 200, a locationin a different hospital, or any other location.

System 150 can include a communication device 155, a display device 160,a first auxiliary input device 165, and a second auxiliary input device180. The structure and function of communication device 155, displaydevice 160, and second auxiliary input device 180 can be substantiallysimilar to the structure and function of communication device 50,display device 60, and auxiliary input device 80, respectively, ofFIG. 1. First auxiliary input device 165 may comprise, for example, ajoystick, a computer mouse, a rollerball, knobs, levers, buttons,touchpads, touchscreens, or any other appropriate control device capableof being used to control manipulator 240. In this example, a medicalprofessional can use first auxiliary input device 165 to controlmanipulator 240 from the remote location.

In this embodiment, system 200 includes a medical device 210, amanipulator 240, a communication device 250, and a display device 260.System 200 also includes a host 270 comprising GUI 272, a thirdauxiliary input device 280, and a system controller 290. Although host270 resides within system 200 in this example, host 270 could residewithin system 150 or could reside in any location accessible to system300 without departing from the scope of the present disclosure. Thestructure and function of medical device 210, manipulator 240,communication device 250, display device 260, host 270, GUI 272, thirdauxiliary input device 280, and system controller 290 can besubstantially similar to the structure and function of medical device10, manipulator 40, communication device 50, display device 60, host 70,GUI 72, auxiliary input device 80, and system controller 90,respectively, of FIG. 1.

System 150 communicates with system 200 over communication link 305.Although communication link 305 comprises a single communication link inthis example, any other number of communication links may be usedwithout departing from the scope of the present disclosure.Communications link 305 may include any hardware, software, firmware, orcombination thereof. In various embodiments, communications link 305 maycomprise a communications medium capable of assisting in thecommunication of analog and/or digital signals. Communications link 305may, for example, comprise a twisted-pair copper telephone line, a fiberoptic line, a Digital Subscriber Line (DSL), a wireless link, a USB bus,a PCI bus, an Ethernet interface, or a combination of these or otherelements.

In some embodiments, a first medical professional can manually insertmedical device 210 into a patient. In those cases, system 200 cancommunicate data to a second medical professional using remote system150 through communication link 305. The second medical professional,while monitoring display device 160, can remotely manipulate medicaldevice 210 using voice instructions communicated through communicationdevice 155 coupled to communication link 305 to host 270. In thismanner, the medical professional using system 150 can substantiallyemulate a medical professional's manual control of medical device 210.In other embodiments, the medical professional can remotely manipulatemedical device 210 using auxiliary devices 165 and/or 180. In analternative embodiment, a medical professional can insert medical device210 into a patient using system 200 locally or using system 150remotely.

In addition to voice command control and/or auxiliary input devicecontrol, other methods of medical device control may be implemented. Insome cases, system 150 and/or system 200 can implement aheads-up-display (HUD) capable of controlling and/or manipulatingmedical device 210 and/or manipulator 240. The HUD may be capable ofprojecting images onto or near the eyes of a medical professional andcapable of sending command signals using a virtual control deviceattached to the medial professional. In another example, the medicalprofessional may wear a helmet capable of manipulating medical device210 and/or manipulator 240 based at least in part on command signalsgenerated in response to a motion associated with the head of themedical professional. For example, rotation of the head to the right mayindicate that the operator wants the medical device to move to theright.

FIG. 3 illustrates an example medical device 400. In variousembodiments, at least a portion of medical device 400 may be insertedinto a patient's body through an orifice during a medical procedure. Theorifice may comprise, for example, the patient's throat or mouth, thepatient's nasal passages, an incision made during surgery, or any othersuitable orifice. In this particular example, medical device 400comprises a scope. The scope may comprise, for example, an endoscope, acolonoscope, a gastroscope, a enteroscope, a bronchoscope, alaryngoscope, a choledochoscope, a sigmoidoscope, a duodenoscope, aarthoroscope, a cystoscope, a hyteroscope, a laparoscope, or acombination of these or any other suitable device. In variousembodiments, medical device 400 can be controlled through, for example,voice commands, auxiliary input command, automated commands, and/ormanual commands. In some cases, medical device 400 can be coupled to amedical device control system, such as system 100 or system 300 of FIG.1 and FIG. 2, respectively.

Medical device 400 includes a base portion 410 capable of controllingand/or at least partially contributing to the manipulation of aninsertable portion 420. In this example, base portion 410 includescontrol system 435 capable of at least partially contributing to thecontrol and/or the manipulation of insertable portion 420. Controlsystem 435 may be capable of receiving, processing, executing, and/orcommunicating one or more signals associated with the manipulation ofinsertable portion 420. In various embodiments, these signals receivedby base portion 410 may comprise, for example, voice commands, auxiliaryinput commands, automated commands, physiological parameters, videodata, positioning data, or a combination of these or other signal types.

In various embodiments, control system 435 may reside in a locationoutside of base portion 410 and/or may be partially or wholly includedwithin base portion 410. Control systems 435 may comprise, for example,a mechanical control system, an electrical control system, anelectro-mechanical control system, or a combination of these or anyother suitable control system. The phrase “mechanical control system”refers to a control system that at least partially includes mechanicalcomponents. Mechanical control systems can include, for example,hydraulic components, pneumatic components, pulleys, guidewires, gears,actuators, pushrods, sprocket/chain mechanisms, feedback controlcircuitry, or any other suitable components.

In this particular embodiment, control system 435 includes a manualoverride control module 411, an x-axis control module 412, a y-axiscontrol module 414, and a z-axis control module 416. Control modules411, 412, 414, and 416 may include any hardware, software, firmware, orcombination thereof. In some embodiments, control modules 411, 412, 414,and 416 may comprise buttons, knobs, dials, control circuitry, or anyother suitable control input device. In this particular embodiment,control modules 412, 414, and 416 operate to receive and process inputsignals from a medical professional. In addition, control modules 412,414, and 416 operate to at least partially contribute to themanipulation of insertable portion 420. The input signals may comprise,for example, voice commands, auxiliary input commands, and/or manualinput commands. In other embodiments, control modules 412, 414, and 416operate to receive and process input signals from a host and/or systemcontroller. For example, a medical professional can use control modules412, 414, and 416 to individually control medical device 400 in the x-,y-, and z-axes, respectively. In various embodiments, override controlmodule 411 may be capable of enabling the medical professional tooverride the automatic operation of medical device 400 as necessaryduring a medical procedure.

Control system 435 may also include touch-screen 417 and controller 418.Controller 418 operates to combine the individual control functions ofcontrol modules 412, 414, and 416 into a single controller. For example,a medical professional can use controller 418 and/or touch-screen 417 tomanually control medical device 400 in the x-, y-, and z-axes,respectively. Controller 418 can comprise any device capable ofcontrolling the manipulation of insertable portion 420. Controller cancomprise, for example, a joystick, a rollerball, knobs, levers, buttons,or any other appropriate control device.

Control system 435 further includes motors 436, pulleys 432, andguidewires 434. Although motors, pulleys, and guidewires are used inthis example, control system 435 can include any other componentscapable of contributing to the manipulation of insertable portion 420without departing from the scope of the present disclosure. In thisexample, motors 436 operate to control the positioning of insertableportion 420 based at least in part on control signals received frommodules 411, 412, 414, and 416, and/or controller 418. Motors 436operate to manipulate guidewires 434 coupled to one end of insertableportion 420. In other embodiments, base unit 410 includes actuators,pushrods, sprocket/chain mechanisms, feedback control circuitry, or anyother control mechanism appropriate to control insertable portion 420.

In this example, pulleys 432 and motors 436 operate to control thetension in guide wires 434. In some embodiments, each guidewire 434 maycomprise two or more segments, each segment comprising a differentradial stiffness. For example, a first segment of guidewire 434 may becoupled to pulley 432, and a second segment of guidewire 434 may becoupled to an end of insertable portion 420. In that example, the secondsegment of guidewire segment may have a radial stiffness that is lessthan a radial stiffness associated with the first segment guidewire. Invarious embodiments, the force exerted by guidewires 434 can causeinsertable portion 430 to move in a corresponding manner.

Medical device 400 may also include insertable portion 420 connected tobase portion 410 and capable of being inserted into an orifice orincision in a patient's body during a medical procedure. In thisparticular embodiment, a medical profession can, using base portion 410,manipulate insertable portion 420 in the patient's body to perform amedical procedure. In various embodiments, a medical professional cancontrol insertable portion 420 using voice commands, auxiliary inputcommands, automated commands, and/or manually.

In this example, insertable portion 420 includes a flexible portion 430and an automated head unit 440. In this particular embodiment, one endof each guidewire 434 is connected to one end of automated head unit440, while the other end of each guidewire 434 is connected to one ofpulleys 432. Although pulleys and guide wires are used to manipulateautomated head unit 440, any other appropriate control mechanism may beused without departing from the scope of the present disclosure. In thisexample, control system 435 operates to create tension in guide wires434. The tension in guidewires 434 operates to exert a force onautomated head unit 440, which causes automated head unit 440 to move ina corresponding manner. For example, control system 435 may operate toapply tension to one or more guidewires 434 creating a force in thex-plane, which causes automated head unit 440 to move in the x-plane.Any suitable movement of automated head unit 440 in the x-y plane tendsto impart a corresponding movement to flexible portion 430 in the x-yplane.

In this example, four guide wires 434 are used to manipulate automatedhead unit 440 with two guidewires 434 connected along the x-axis and twoguidewires 434 connected along the y-axis. In an alternative embodiment,six or more guidewires 434 may be positioned around the periphery of theinsertable portion 420, which can allow a medical professional moreprecise control of medical device 400. In some cases, the movement ofautomated head unit 440 may be controlled independently of the movementof flexible portion 430. In some embodiments, flexible portion 430 andautomated head unit 440 may operate as “telescoping” tubes, whereautomated head unit 440 may retract into and extend from flexibleportion 430 to adjust a length (L) of insertable portion 420. Such atelescoping motion may be controlled through the positioning of pulleys432 and guidewires 434.

In this particular embodiment, control modules 412, 414, and/or 416receive and process command signals corresponding to a desiredmanipulation of insertable portion 420. Control module 412 and controlmodule 414 are operable to control the motion of automated head unit 440and the entire insertable portion 420 in the x-axis and y-axis,respectively. In some embodiments, control module 416 is operable toadjust the distance that automated head unit 440 moves relative toflexible portion 430. In those cases, control module 416 is operable tocause motor 436 to position the pulleys 432 and guidewires 434 so as toextend and retract automated head unit 440 relative to flexible portion430. Control module 412 and control module 414 are operable toindependently control the motion of automated head unit 440 regardlessof length L, enabling insertable portion 420 to have independent motionin the x-, y-, and z-axes.

Insertable portion 420 may also include sensors 442 and a camera 444.Although this example depicts sensors 442 as being connected toautomated head unit 440, sensors may be connected to any portion ofmedical device 400 without departing from the scope of the presentdisclosure. Injury may occur when a medical professional accidentally ormistakenly causes insertable portion 420 to contact tissue associatedwith the patient, which can cause bruising or damage to the tissue.Sensors 442 can comprise any device capable of providing data and/or asignal to a medical professional. Sensors 442 may be capable ofgenerating and transmitting, for example, positioning informationassociated with insertable portion 420, physiological informationassociated with the patient, control signals, a signal indicating thepresence or absence of blood, or any other data. In one particularembodiment, sensors 442 are capable of generating and transmitting dataassociated with insertable portion's 420 proximity to tissue of thepatient.

In other embodiments, sensors 442 may be capable of detecting acollision with tissue. In those cases, sensors 442 are capable ofgenerating and transmitting a feedback signal to control modules 412,414, 416, a host coupled to medical device 400, or a system controllercoupled to medical device 400. For example, sensors 442 may communicatedata indicating that wall tissue of a patient's orifice has beenencountered and that device 400 may need to be directed away from thatwall to prevent injury to the patient's tissue. In some embodiments,sensors 442 operate to generate alarms associated with medical device400. For example, one or more sensors 442 may monitor the presence ofblood in the orifice, so that the medical professional may be alerted tounexpected or excessive bleeding.

In operation, medical device 400 may be inserted into the patient byinserting insertable portion 420 into the appropriate orifice orincision. In some embodiments, a medical professional can insert medicaldevice 400 into the patient. In other embodiments, the insertion ofmedical device 400 into the patient may be performed using a medicaldevice control system implementing a manipulator, such as system 100 andmanipulator 40 of FIG. 1 or system 300 and manipulator 240 of FIG. 2.

In this particular embodiment, medical device 400 is capable of beingmanipulated in at least three axes of motion. That is, medical device400 is capable of being manipulate in the x-axis, y-axis, and z-axis. Inother embodiments, medical device 400 is capable of being manipulated inat least two axes of motion. In some embodiments, medical device 400 maybe capable of manipulating insertable portion 420 one axis at a time. Inother embodiments, medical device 400 may be capable of manipulatinginsertable portion 420 one axis at a time and manipulating insertableportion 420 along multiple axes substantially simultaneously. In thisexample, medical device 400 is capable of manipulating insertableportion 420 along multiple axes substantially simultaneously. As usedthroughout this document, the phrase “substantially simultaneously”refers to the manipulation of insertable portion 420 and/or automatedhead unit 440 in multiple axes in response to an input command beforeresponding to a subsequent input command. For example, medical device400 can manipulate insertable portion 420 along the z-axis and, duringthat manipulation, medical device 400 can also manipulate insertableportion 420 along the x-axis. In various embodiments, medical device 400can manipulate automated head unit 440 independently of the movement offlexible portion 430.

FIG. 4 is a block diagram illustrating a flow of command signals from amedical professional to a medical device in a medical device controlsystem 500. In various embodiments, medical device control system 500can be substantially similar to control system 100 of FIG. 1 or controlsystem 300 of FIG. 2. In this example, a communication device 550receives a voice command 502 from a medical professional. In variousembodiments, the structure and function of communication device 550 canbe substantially similar to the structure and function of communicationdevice 50 of FIG. 1. Communication device 550 operates to convert voicecommand 502 into an electrical voice command signal 504 and tocommunicate electrical voice command signal 504 to a system controller590. In various embodiments, the structure and function of systemcontroller 590 can be substantially similar to the structure andfunction of system controller 90 of FIG. 1.

In this particular embodiment, system controller 590 comprises a voicerecognition module 592 capable of at least partially contributing to oneor more functions of system controller 590. That is, voice controlmodule 592 is not required to be capable of performing the desiredfunctionality of system controller 590 alone, but may contribute to theperformance of the function as part of a larger routine. In thisexample, voice recognition module 592 at least partially contributes tothe conversion of voice command signal 504 to a control signal 506.Voice recognition module 592 may include any hardware, software,firmware, or any combination thereof that is capable of converting voicecommand signal 504 into control signal 506.

System controller 590 also includes a command generator module 594capable of at least partially contributing to one or more functions ofsystem controller 590. In this example, command generator module 594operates to receive control signal 506 communicated from voicerecognition module 592 and at least partially contributes to theconversion of control signal 506 into a command signal 508. Commandgenerator 594 may comprise any hardware, software, firmware, or anycombination thereof that is capable of converting control signal 506into command signal 508. In this example, command generator module 594communicates command signal 508 to a signal generator module 596 capableof at least partially contributing to one or more functions of systemcontroller 590. In this example, signal generator module 596 at leastpartially contributes to the conversion of command signal 508 into anactuation signal 510. Signal generator 596 may comprise any hardware,software, firmware, or any combination thereof that is capable ofconverting command signal 508 into actuation signal 510.

In this example, system controller 590 communicates actuation signal 510to a device control module 560 capable of manipulating a medical device570. In various embodiments, the structure and function of devicecontrol module 560 can be substantially similar to the structure andfunction of actuation unit 20 of FIG. 1 or base portion 410 of FIG. 3.In various embodiments, the structure and function of medical device 570can also be substantially similar to the structure and function ofmedical device 10 of FIG. 1 or medical device 400 of FIG. 3.

In various embodiments, device control module 560 may be capable ofgenerating a feedback signal 512 and communicating feedback signal 512to system controller 590. Feedback signal 512 may comprise, for example,positioning data associated with medical device 570, a video feed, aphysiological parameter associated with a patient, or any otherinformation associated with medical device 570, device control module560, and/or a patient undergoing a medical procedure. In someembodiments, medical device 570 can communicate data 514 to systemcontroller 590. Data 514 may comprise, for example, positioning data,one or more physiological parameters associated with a patient, a livevideo feed associated with a camera coupled to medical device 570, orany other data capable of being collected by medical device 570.

In various embodiments, system controller 590 may be capable ofgenerating commands on its own based at least in part on data 514 and/orfeedback signal 512 communicated from medical device 570 and/or devicecontrol module 560. For example, if medical device 570 comprises a scopewith blood sensors, system controller 590 may stop the movement of thescope within a patient's body if data 514 is received from medicaldevice 570 indicating that the patient is bleeding excessively.

In this example, system 500 also includes a display device 580 capableof displaying data associated with medical device 570 and/or a patient.The structure and functional of display device 580 can be substantiallysimilar to the structure and function of display device 60 or GUI 72 ofFIG. 1. Although system 500 includes a single display device in thisexample, any other number of display devices may be used withoutdeparting from the scope of the present disclosure. In some embodiments,system controller 590 can communicate an output signal 516 containingdata associated with medical device 570 and/or a patient to displaydevice 580.

In some embodiments, system 500 may also includes an audio output device587 capable of communicating data associated with medical device 570and/or a patient. Audio output device 587 can comprise any devicecapable of providing an audio output signal, such as a speaker,headphones, an audio alarm device, or any other suitable audio outputdevice. Although system 500 includes a single audio output device inthis example, any other number of audio output devices may be usedwithout departing from the scope of the present disclosure. In someembodiments, system controller 590 may communicate an audio outputsignal 516 to output device 587 so that the medical professional mayreceive the data associated with output signal 516 in audio format.

Although, in most cases, voice command 502 represents the primarycontrol input into system 500, system 500 also includes an auxiliaryinput device 585 capable of generating a control signal 518. Controlsignal 518 can comprise data that is substantially similar to datacontained within control signal 506. In various embodiments, thestructure and function of auxiliary input device 585 can besubstantially similar to the structure and function of auxiliary inputdevices 165 or 180 of FIG. 2. Although system 500 includes a singleauxiliary input device in this example, any other number of auxiliaryinput devices may be used without departing from the scope of thepresent disclosure. In this particular embodiment, auxiliary inputdevice 585 is coupled directly to command generator 594. In someembodiments, auxiliary input device 585 may also receive data signals520 from system controller 590. For example, in a case where auxiliaryinput device 585 comprises a “force-feedback” joystick, signals 520 maycomprise the feedback signal representing the force being exerted onmedical device 570 by the patient's body.

FIG. 5 is a flow chart illustrating an exemplary method 600 forprocessing a voice control signal and/or a command signal received by amedical device control system. In one particular embodiment, voicecontrol signals and/or command signals are received from system 100 ofFIG. 1. Although system 100 is used in this example, any other system,such as systems 300 and 500 of FIGS. 2 and 4, respectively, may be usedwithout departing from the scope of the present disclosure.

In this example, method 600 begins at step 602 where communicationdevice 50 receives a voice command from a medical professional.Communication device 50 operates to convert the voice command into voicecommand signal 57 and communicates voice command signal 57 to host 70.In this particular example, host 70 includes a voice recognition modulethat processes voice command signal 57 at step 604 by converting voicecommand signal 57 into a control signal. In various embodiments, thestructure and function of the voice recognition module can besubstantially similar to voice recognition module 592 of FIG. 4. In thisexample, the voice recognition module further operates to identify thespecific voice command represented by the control signal at step 606. Insome embodiments, identifying the specific voice command may beaccomplished by comparing the received control signal with a list ofpre-programmed commands stored in a memory device associated with host70.

The voice recognition module validates the control signal at step 608.If the voice command is not recognized as a pre-programmed command, theinvalid voice command is ignored and the method loops back to step 602.If the voice command is valid, the voice recognition module communicatesthe control signal to a command generator. In this example, the commandgenerator operates to convert the control signal into a command signalrepresenting the voice command at step 610. In various embodiments, thestructure and function of the command generator can be substantiallysimilar to the structure and function of command generator module 594 ofFIG. 4.

In an alternate embodiment, auxiliary control signals capable ofmanipulating a medical device may be generated by an auxiliary inputdevice at step 616. In various embodiments, the auxiliary input devicemay comprise, for example, auxiliary input devices 165 and/or 180 ofFIG. 2. The auxiliary input device communicates the auxiliary controlsignal to the command generator, which coverts the auxiliary controlsignal into a command signal at step 610. The command generator alsooperates to communicate the command signal to a signal generator.

In this example, the signal generator operates to convert the commandsignal into an actuation signal 47 representing the voice command of themedical professional at step 612. In various embodiments, the structureand function of the signal generator can be substantially similar to thestructure and function of signal generator module 596 of FIG. 4. In thisexample, manipulator 40 and/or medical device 10 operates to receive andexecute actuation signal 47 at step 614.

Medical devices, such as a scope, that are adapted to be inserted intothe patient's body typically permit the introduction of a waveguidestructure or other wired device through the patient's orifice. Thewaveguide structure can comprise, for example, an optical fiber, ahollow tube waveguide, an air core waveguide, a planar waveguide, or acombination of these or other devices. Examples of such additionaldevices include, for example, surgical knives, sample collectors, and/orcauterizing heads. In some cases, inserting a waveguide structure mayenable, for example, the early detection of cancerous cells and maycontribute to the removal of the cancerous cells. In variousembodiments, the waveguide structure may communicate an optical signalwavelength of 1.7 microns or more.

In some embodiments, a waveguide structure may be implemented in amedical device that uses an optical signal wavelength in themid-infrared (mid-IR) wavelength range to perform surgery and/orspectroscopy on a patient. In various embodiments, a wavelength in themid-IR range comprises a wavelength between approximately two (2)microns and approximately ten (10) microns. In other embodiments, awavelength in the mid-IR range comprises a wavelength betweenapproximately five (5) and seven (7) microns. For light-based surgeryand spectroscopy, it can be particularly advantageous to use an opticalsignal wavelength in the range between approximately 5 microns toapproximately 7 microns to minimize tissue damage or collateral damage.In a particular embodiment, an optical signal having a wavelength ofapproximately 6.45 microns may be advantageously used for light-basedsurgery and/or spectroscopy.

In some embodiments, a Raman wavelength shifter coupled to a pump laseris capable of generating an optical signal wavelength in the mid-IRrange. As used in this document, the phrase “Raman wavelength shifter”refers to any device that uses the Raman effect to shift a shorteroptical signal wavelength to a longer optical signal wavelength. TheRaman wavelength shifters may comprise, for example, one or morereflectors, one or more gratings, an optical fiber, or a combination ofthese or other elements. In various embodiments, the Raman wavelengthshifter may comprise, for example, a chalcogenide glass fiber that iscapable of shifting the shorter pump laser wavelength to a longerwavelength, such as a wavelength in the mid-IR region. The chalcogenidefiber may comprise, for example, a ZBLAN fiber, a sulphide fiber, aselenides fiber, or a telluride fiber, or a combination of these orother fiber types.

In other embodiments, a first wavelength shifter coupled to a pump lasermay be capable of shifting an optical signal wavelength to approximately2 microns. The first wavelength shifter may comprise, for example, afused silica optical fiber capable of shifting the shorter pump laserwavelength to approximately two (2) microns. In that example, a secondRaman wavelength shifter is coupled to the first Raman wavelengthshifter and is capable of shifting the two (2) micron signal to awavelength in the five (5) to seven (7) micron range. In that example,the second Raman wavelength shifter comprises a chalcogenide glassfiber.

FIG. 6A compares a surgical incision made using a 2.94 micron opticalsignal wavelength to a surgical incision made using a 6.45 micronoptical signal wavelength. This figure illustrates that tissue damage,such as denatured tissue, can result when a medical device implements a2.94 micron optical signal wavelength. This tissue damage tends toresult from the protein temperatures in the tissue do not uniformlyexceed the water temperature in the aqueous components of the tissue.

Compared to the incision performed using the 2.94 micron optical signalwavelength, the incision made using the 6.45 micron optical signal haslittle or no denatured tissue. This reduction in collateral tissuedamage is based at least in part on the tissue's ability to absorbdifferential energy. For example, when using an optical signalwavelength at approximately 6.45 microns to create an incision, theprotein temperatures in the tissue uniformly exceed the watertemperature in the tissue and the protein begins to transform intobrittle denatured protein. The brittle fracture of the proteins at theonset of explosive vaporization leads to the confinement of collateraldamage. Therefore, the use of a 6.45 micron optical signal wavelength asa tissue cutting implement may minimize collateral tissue damage duringlaser-based surgery. By using an optical signal wavelength of 6.45microns with a medical scope-type device, “clean” surgery may beperformed for many medical procedures, such as removing cancerouspolyps. Similar results can be obtained using an optical signalwavelength in the five (5) to seven (7) micron range.

FIG. 6B illustrates example evanescent spectra in different cell-typeregions (using a mouse as the biological sample). This figureillustrates that cancerous cells tend to show a distinct reduction 700in transmission at an optical signal wavelength of approximately 6.1microns. Medical professionals can exploit this spectral signature invarious medical procedures, such as a procedure for the early detectionof cancer. Thus, an optical signal wavelength in the mid-IR range may beused to perform a medical procedure for the early detection of tissueabnormalities such as cancer cells. In other embodiments, an opticalsignal wavelength in the mid-IR range can be used in a diagnosticprocedure, such as spectroscopy. Diagnostic techniques capable of usingthe mid-IR optical signal wavelength include, for example, transmission,reflection, fluorescence, and near field microscopy. Although specificexamples of spectroscopy are discussed, any other appropriate form ofspectroscopy may be used without departing from the scope of thisdisclosure.

To improve the signal-to-noise ratio of a spectroscopic measurement suchas in FIG. 6B, several methodologies may be used. First, a differentialmeasurement may be taken between a known cancer-free area and thesuspect area, for example, differential spectroscopy rather thanabsolute spectroscopy. In addition, measurements may be taken at severalwavelengths and compared to each other. For example, measuring thedifferential transmission of the tissue at two or more wavelengths, suchas 5 microns and 6.1 microns, may improve the signal-to-noise ratio ofthe cancer cell signature.

FIG. 7 illustrates example attenuation characteristics of severaloptical fibers based on wavelength. This example shows that fused silica(SiO₂) fibers become lossy above approximately 2 microns in wavelength,while mid-IR optical fibers remain relatively loss-less above 2 microns.A mid-IR fiber may comprise any optical fiber capable of at leastpartially transmitting for at least a portion of the mid-IR range. Forexample, a mid-IR fiber may comprise a chalcogenide fiber, such as aSulfide fiber, a Selenide fiber, or a Telluride fiber. Therefore, insome cases, a pump source coupled to a medical device, such as medicaldevice 400 of FIG. 3, may comprise a high powered pump source coupled toa Raman wavelength shifter comprising a mid-IR fiber. In a particularembodiment, such a pump source may operate in a pulsed mode or in acontinuous wave mode. The power levels required depend on the particularapplication. For example, spectroscopy may require a relatively lowpower level, while surgery may require a relatively high power level.

Conventional surgical devices capable of using a 5.0 to 6.5 micronoptical signal wavelength typically implement a Free Electron Laser(FEL) pump source. However, a FEL pump source is a large and veryexpensive facility that tends to be impractical for surgicalapplications. Unlike conventional surgical devices, a medical device,such as device 400 of FIG. 3, can include a pump laser coupled to one ormore Raman wavelength shifters capable of shifting a shorter signalwavelength to a longer signal wavelength. In that example, at least aportion of the Raman wavelength shifter can be implemented in awaveguide structure. In various embodiments, the longer signalwavelength can comprise, for example, an optical signal wavelength inthe mid-IR wavelength range. Coupling a pump laser to one or more Ramanwavelength shifters can result in a commercially and economically viableoptical cutting implement for use in a medical device. In addition,coupling a pump laser to one or more Raman wavelength shifters canresult in a significantly smaller footprint area than a FEL pump sourceand can significantly reduce the cost.

Conventional wavelength shifters or oscillators are typicallyimplemented in fused silica fiber. The loss associated with fused silicafiber tends to increase rapidly for optical signal wavelengths greaterthan about 2 or 2.3 microns. Unlike conventional wavelength shifters, amedical device, such as device 400 of FIG. 3, can include a Ramanwavelength shifter or oscillator that is capable of transmitting in themid-IR wavelength range, such as chalcogenide optical fibers.

FIGS. 8A through 8D are block diagrams illustrating example embodimentsof Raman wavelength shifters and/or Raman oscillators capable ofshifting a shorter pump signal wavelength to a longer output signalwavelength. Although particular examples of wavelength shifters aredescribed in FIGS. 8A through 8D, any other Raman wavelength shifter canbe implemented without departing from the scope of the presentdisclosure.

FIG. 8A is a block diagram illustrating one example of a Ramanwavelength shifter 800 capable of shifting a shorter pump signal 810wavelength to a longer output signal wavelength 812. In this example,Raman wavelength shifter 800 operates to generate an optical signalwavelength 812 of 1.7 microns or more. In various embodiments, Ramanwavelength shifter 800 can operate to generate an optical signalwavelength 812 in the mid-IR wavelength range. In other embodiments,Raman wavelength shifter 800 can operate to generate an optical signalwavelength 812 a wavelength in the five (5) to seven (7) micron range.In various embodiments, pump signal 810 can comprise, for example, a1310 nanometer (nm) wavelength, 1390 nm wavelength, 1510 nm wavelength,or other optical signal wavelength.

Raman wavelength shifter includes a gain fiber 804 operable tofacilitate shifting pump signal 810 to a desired wavelength. Gain fiber804 may comprise any waveguide structure capable of wavelength shiftingpump signal 810 to a longer wavelength or a different Raman cascadeorder. In this particular embodiment, gain fiber 804 comprises anoptical fiber. The optical fiber used as gain fiber 804 may comprise,for example, a dispersion compensating fiber, a dispersion shifterfiber, a single mode fiber, a chalcogenide fiber, a fused silica opticalfiber, or a combination of these or other fiber types. Raman wavelengthshifter 800 also includes a broadband reflector 802 operable tosubstantially reflect all optical signal wavelengths contained withinRaman wavelength shifter 800 and a pump signal coupler 806. Reflector802 may comprise any device capable of reflecting a wide range ofwavelength signals, such as a mirror. Pump signal coupler 806 maycomprise any device capable of coupling pump signal 810 to Ramanwavelength shifter 800, such as a wavelength division multiplexer or apower coupler.

In this example, Raman wavelength shifter 800 further includes awavelength separator 808 capable of transmitting at least a portion ofthe desired wavelength from Raman wavelength shifter 800. In addition,wavelength separator 808 operates to at least partially reflect adesired wavelength to gain medium 804 to continue lasing at the desiredwavelength or wavelengths. In this particular embodiment, a cavity isformed between reflector 802 and wavelength separator 808. Separator 808could comprise, for example, a demultiplexer, one or more partiallytransmissive gratings, one or more partially transmitting mirrors, oneor more Fabry Perot filters, one or more dielectric gratings, or anycombination of these or other devices.

FIG. 8B is a block diagram illustrating one example of a Ramanwavelength shifter 820 capable of shifting a shorter pump signal 830wavelength to a longer output signal wavelength 832. In this example,Raman wavelength shifter 820 operates to generate an optical signalwavelength 832 of 1.7 microns or more. In various embodiments, Ramanwavelength shifter 820 operates to generate an optical signal wavelength832 in the mid-IR wavelength range. In other embodiments, Ramanwavelength shifter 820 operates to generate an optical signal wavelength832 a wavelength in the five (5) to seven (7) micron range. In variousembodiments, pump signal 830 can comprise, for example, a 1310 nanometer(nm) wavelength, 1390 nm wavelength, 1510 nm wavelength, or otheroptical signal wavelength.

In this example, Raman wavelength shifter 820 includes a reflector 822,a gain fiber 824, a pump input coupler 826, and a wavelength separator828. In various embodiments, the structure and function of reflector822, gain fiber 824, coupler 826, and separator 828 can be substantiallysimilar to reflector 802, gain fiber 804, coupler 806, and separator 808of FIG. 8A, respectively. In this particular embodiment, at least aportion of gain fiber 824 can comprise a chalcogenide fiber.

Raman wavelength shifter 820 may also include at least a first selectingelement 825 a and a second selecting element 825 b. Although thisexample may also include two selecting elements 825 a and 825 b, anynumber of selecting elements can be used without departing from thescope of the present disclosure. Selecting elements 825 a and 825 b cancomprise any device, such as a dielectric grating or one or more FabryPerot filters. Each selecting element operates to transmit a portion ofa desired wavelength to be output from Raman wavelength shifter 820. Inaddition, each selecting element 825 a and 825 b operates to at leastpartially reflect a desired wavelength to gain medium 824 to allowwavelength shifter 820 to continue lasing at the desired wavelength orwavelengths. In this particular embodiment, an optical cavity is formedbetween reflector 822 and selecting element 825 a and/or selectingelement 825 b.

FIG. 8C is a block diagram illustrating one example of a Ramanwavelength shifter 840 capable of shifting a shorter pump signal 850wavelength to a longer output signal wavelength 852. In this example,Raman wavelength shifter 840 operates to generate an optical signalwavelength 852 of 1.7 microns or more. In various embodiments, Ramanwavelength shifter 840 operates to generate an optical signal wavelength852 in the mid-IR wavelength range. In other embodiments, Ramanwavelength shifter 840 operates to generate an optical signal wavelength852 a wavelength in the five (5) to seven (7) micron range. In variousembodiments, pump signal 850 can comprise, for example, a 980 nanometer(nm) wavelength, a 1060 nm wavelength, a 1310 nm wavelength, a 1390 nmwavelength, a 1510 nm wavelength, or other optical signal wavelength.

In this example, Raman wavelength shifter 840 includes a gain fiber 844,a pump input coupler 846, and selecting elements 845. In variousembodiments, the structure and function of gain fiber 844, coupler 826,selecting elements 845, and output coupler 848 can be substantiallysimilar to gain fiber 824, coupler 826, selecting elements 825, andcoupler 828 of FIG. 8B, respectively. In this particular embodiment, atleast a portion of gain fiber 824 can comprise a chalcogenide fiber.

The example illustrated in FIG. 8C differs from the example illustratedin FIG. 8B in that wavelength shifter 840 implements a plurality ofreflective gratings 847 a-847 n each centered on a different wavelengthof a reflection band. Although this example includes three gratings, anynumber of gratings can be used without departing from the scope of thepresent disclosure. Gratings 847 a-847 n can comprise any device, suchas a high-reflectivity dielectric grating. In this particular example,each grating 847 a-847 n comprises a grating with a reflectivity betweenninety-five (95) to one hundred (100) percent at the center wavelength.Gratings 847 a-847 n operate to facilitate cascading of pump signal 850to a desired output wavelength. In this particular embodiment, anoptical cavity is formed between selecting elements 845 are gratings847.

FIG. 8D is a block diagram illustrating one example of a Ramanwavelength shifter 860 capable of shifting a shorter pump signal 870wavelength to a longer output signal wavelength 832. In this example,Raman wavelength shifter 860 operates to generate an optical signalwavelength 872 of 1.7 microns or more. In various embodiments, Ramanwavelength shifter 860 operates to generate an optical signal wavelength872 in the mid-IR wavelength range. In other embodiments, Ramanwavelength shifter 860 operates to generate an optical signal wavelength872 a wavelength in the five (5) to seven (7) micron range. In variousembodiments, pump signal 870 can comprise, for example, a 980 nmwavelength, a 1060 nm wavelength, a 1310 nm wavelength, a 1390 nmwavelength, a 1510 nm wavelength, or other optical signal wavelength.

In this example, Raman wavelength shifter 860 includes a gain fiber 864,a pump input coupler 866, selecting elements 864, reflective gratings867, and an output coupler 868. In various embodiments, the structureand function of gain fiber 864, input coupler 866, elements 864,gratings 867, and output coupler 868 can be substantially similar togain fiber 844, coupler 846, elements 845, gratings 847, and coupler 848of FIG. 8C, respectively. Although example elements are illustrated,Raman wavelength shifter 860 may include some, none, or all of theseelements. For example, in some embodiments, pump input coupler 866and/or output coupler 868 may be optional.

The example illustrated in FIG. 8D differs from the example illustratedin FIG. 8C in that wavelength shifter 860 implements a Q-switcher 863capable of transitioning from a reflective state to a transmissivestate. Q-switcher 863 can comprise a device or combination of deviceshaving a variable loss. For example, Q-switcher may comprise one or moremoving mirrors, electro-optic switches, saturable absorbers, or acombination of these or other optical devices. In some cases, Q-switcher863 can initially operate as a reflective mirror so that optical signalenergy may build-up within the laser cavity. After the laser cavitycontains a sufficient amount of optical energy, Q-switcher 863 canoperate to substantially transmit the desired optical signal wavelengthin the form of a relatively large pulse or burst. In variousembodiments, Q-switcher 863 may be capable of providing an output signalhaving a pulse width in the range of two (2) nanoseconds to one hundred(100) milliseconds. In other embodiments, Q-switcher 863 may be capableof providing an output signal having a pulse repetition rate in therange of two (2) hertz to one hundred (100) megahertz.

FIGS. 9A through 9C are block diagrams illustrating example embodimentsof pump sources that are capable of generating a pump signal for use ina Raman wavelength shifter. Although particular examples of pump sourcesare described in FIGS. 9A through 9C, any other pump source can beimplemented without departing from the scope of the present disclosure.

FIG. 9A is a block diagram illustrating one example embodiment of a pumpsource 900 capable of being coupled to a Raman wavelength shifter and/ora Raman oscillator. Pump source 900 can comprise any device capable ofgenerating an optical signal at a desired wavelength and power. Forexample, pump source 900 can comprise a solid state laser, such a Nd:YAGor Nd:YLF laser, a semiconductor laser, a laser diode, a cladding pumpfiber laser, or any combination of these or other light sources. In thisexample, pump source 900 comprises a high powered laser 902 coupled to aRaman oscillator or a Raman wavelength shifter, such as Raman wavelengthshifters 800, 820, 840, or 860 of FIGS. 8A through 8D.

FIG. 9B is a block diagram illustrating one example embodiment of a pumpsource 920 capable of being coupled to a Raman wavelength shifter and/ora Raman oscillator. In this example, pump source 920 includes a pumplaser 922 and an intermediate stage 924 capable of shifting the opticalsignal wavelength generated by pump laser 922 to a longer wavelength.The structure and function of laser 922 may be substantially similar tothe structure and function of pump source 900 of FIG. 9A. In thisparticular example, intermediate state 924 comprises a first Ramanwavelength shifter 924. In some embodiments, intermediate wavelengthshifter 924 may advantageously be implemented using fused silica opticalfiber.

In some embodiments, pump sources 900 and 920 may comprise acladding-pumped fiber laser, capable of emitting a pump signalwavelength of approximately 1 micron. In those examples, pump sources900 and 920 can be coupled to a first or auxiliary cascaded Ramanoscillator or Raman wavelength shifter. In some cases, the auxiliaryRaman oscillator or Raman wavelength shifter may comprise, for example,Raman wavelength shifters 800, 820, 840, or 860 of FIGS. 8A through 8Dimplementing a fused silica optical fiber. Such an arrangement may beused to shift the 1 micron optical signal to approximately 2 to 2.3microns. The 2-2.3 micron signal output from the auxiliary Ramanwavelength shifter can then be shifter to a mid-IR wavelength by anothercascaded Raman oscillator or Raman wavelength shifter that implements inmid-IR fiber.

FIG. 9C is a block diagram illustrating one example embodiment of a pumpsource 940 capable of being coupled to a Raman wavelength shifter and/ora Raman oscillator. In this example, pump source 940 includes a pumplaser 942 and a multiplexer 944 capable of combining a plurality of pumpsignals into a pump output signal. In this particular example, pumpsource 900 comprises a first laser diode 942 a and a second laser diode942 b each centered at a desired wavelength and capable of generatingpump signals 943 a and 943 b. Although this example includes two laserdiodes, any number of laser diodes may be used without departing fromthe scope of the present disclosure. In various embodiments, laserdiodes 942 a and 942 b can be centered on substantially the samewavelength, such as 980 nm, 1310 nm, 1390 nm, 14xx nm, or 1510 nm. Inthis particular, pump signals 943 a and 943 b are combined bymultiplexer 944. Multiplexer 944 can comprise any device capable ofcombining pump signals 943, such as a wavelength division multiplexer.In various embodiments, multiplexer 944 can be capable of polarizationand/or wavelength multiplexing pump signals 943 a and 943 b to form apump output signal.

In some embodiments, a Raman wavelength shifter, such as thoseillustrated in FIGS. 8A through 8D, may be used to deliver an opticalsignal wavelength directly to the patient. In other embodiments, asecond mid-IR waveguide structure, that at least partially transmits inat least a portion of the mid-IR wavelength range, may be coupled to theoutput of the Raman wavelength shifter to deliver the optical signalwavelength to the patient. Coupling a second mid-IR waveguide structureto the Raman wavelength shifter can advantageously allow the deliverywaveguide structure to be disposed after use within the patient. Inaddition, coupling a second mid-IR waveguide structure can substantiallyreduce the chance of breaking a fiber associated with a Raman wavelengthshifter. Furthermore, it may be desirable to couple a tapered end orlens on the delivery fiber for improved focusing of optical signal onthe patient.

In various embodiments, an optical signal wavelength is capable of beingdelivered to a medical device inserted into a patient using a waveguidestructure having a relatively low coupling loss. In some cases, thewaveguide structure maintain the coupling loss to, for example, 5 dB orless, 3 dB or less, or even less than 1 dB.

Although the present invention has been described with severalembodiments, a multitude of changes, substitutions, variations,alterations, and modifications may be suggested to one skilled in theart, and it is intended that the invention encompass all such changes,substitutions, variations, alterations, and modifications as fall withinthe spirit and scope of the appended claims.

1. A mid-infrared light source, comprising: a wavelength shifter capableof shifting a shorter optical signal wavelength to a longer opticalsignal wavelength based at least in part on a Raman effect in a firstwaveguide, the longer optical signal wavelength comprising amid-infrared wavelength, at least a portion of the wavelength shiftercomprising a ZBLAN waveguide, and wherein the wavelength shifter ispumped by an intermediate wavelength shifter comprising a secondwaveguide that is substantially different than the ZBLAN waveguide. 2.The mid-infrared light source of claim 1, wherein the longer opticalsignal wavelength is approximately 1.7 microns or more.
 3. Themid-infrared light source of claim 1, wherein the longer optical signalwavelength is in the range of two (2) microns to ten (10) microns. 4.The mid-infrared light source of claim 1, wherein the longer opticalsignal wavelength is in the range of five (5) microns to seven (7)microns.
 5. The mid-infrared light source of claim 1, wherein the ZBLANwaveguide comprises at least a portion of a gain region of the lightsource.
 6. The mid-infrared light source of claim 1, wherein thewavelength shifter further comprises: a first reflector coupled to afirst end of the ZBLAN waveguide; and a second reflector coupled to asecond end of the ZBLAN waveguide.
 7. The mid-infrared light source ofclaim 6, wherein coupling the first and second reflectors operates toform an optical cavity in the light source.
 8. The mid-infrared lightsource of claim 1, wherein the wavelength shifter further comprises: areflector coupled to a first end of the ZBLAN waveguide; and one or moreoptical gratings coupled to a second end of the ZBLAN waveguide.
 9. Themid-infrared light source of claim 1, wherein the wavelength shifterfurther comprises: one or more first optical gratings coupled to a firstend of the ZBLAN waveguide; and one or more second optical gratingscoupled to a second end of the ZBLAN waveguide.
 10. The mid-infraredlight source of claim 1, wherein the wavelength shifter furthercomprises: one or more reflectors coupled to a first end of the ZBLANwaveguide; and a pulse source coupled to a second end of the ZBLANwaveguide.
 11. The mid-infrared light source of claim 1, wherein theshorter optical signal wavelength comprises a pulse width in the rangeof two (2) nanoseconds to one hundred (100) milliseconds.
 12. Themid-infrared light source of claim 1, wherein the shorter optical signalwavelength comprises a pulse repetition rate in the range of two (2)hertz to one hundred (100) megahertz.
 13. The mid-infrared light sourceof claim 1, further comprising a pump laser capable of generating theshorter optical signal wavelength.
 14. The mid-infrared light source ofclaim 13, wherein the pump laser is selected from the group consistingof a continuous wave laser and a pulsed laser.
 15. The mid-infraredlight source of claim 13, wherein the pump laser is selected from thegroup consisting of a Nd:YAG laser, a Nd:YLF laser, laser diodes, asemiconductor laser, and a cladding pumped fiber.
 16. The mid-infraredlight source of claim 1, wherein the intermediate wavelength shiftercomprises at least in part a fused silica fiber and wherein anintermediate output wavelength of the intermediate wavelength shifter isless than 2.5 microns.
 17. The mid-infrared light source of claim 1,wherein the wavelength shifter is coupled to one or more externalwaveguides and wherein a coupling loss between the wavelength shifterand the one or more external waveguides comprises no more than five (5)decibels.
 18. The mid-infrared light source of claim 17, wherein theexternal waveguide comprises one or more optical fibers.
 19. Themid-infrared light source of claim 17, wherein the longer optical signalwavelength is communicated to a portion of a body associated with apatient by the one or more external waveguides coupled to the wavelengthshifter.
 20. The mid-infrared light source of claim 1, wherein the ZBLANwaveguide is selected from the group consisting of an optical fiber, ahollow tube waveguide, an air core waveguide, and a planar waveguide.21. The mid-infrared light source of claim 1, wherein the ZBLANwaveguide is a single mode optical fiber.
 22. A long wavelength lightsource, comprising: a wavelength shifter capable of shifting a shorteroptical signal wavelength to a longer optical signal wavelength based atleast in part on a Raman effect in a waveguide, wherein the wavelengthshifter comprises: a pump laser producing the shorter optical signalwavelength; an intermediate stage coupled to the pump laser andproducing an intermediate optical signal wavelength, wherein theintermediate optical signal wavelength is longer than the shorteroptical signal wavelength; and a final stage operable to generate thelonger optical signal wavelength, wherein the final stage comprises atleast in part a ZBLAN waveguide and wherein the longer optical signalwavelength is greater than 1.7 microns and is greater than theintermediate optical signal wavelength.
 23. The long wavelength lightsource of claim 22, wherein the pump laser is selected from the groupconsisting of a Nd:YAG laser, a Nd:YLF laser, laser diodes, asemiconductor laser, and a cladding pumped fiber.
 24. The longwavelength light source of claim 22, wherein the intermediate stagecomprises at least in part fused silica fiber.
 25. The long wavelengthlight source of claim 22, wherein the ZBLAN waveguide is selected fromthe group consisting of an optical fiber, a hollow tube waveguide, anair core waveguide, and a planar waveguide.
 26. The long wavelengthlight source of claim 22, wherein the longer optical signal wavelengthis greater than 2.8 microns.
 27. The long wavelength light source ofclaim 22, wherein the pump laser is a pulsed laser with a pulse width inthe range of two (2) nanoseconds to one hundred (100) milliseconds. 28.A mid-infrared light source, comprising: a wavelength shifter capable ofshifting a shorter optical signal wavelength to a longer optical signalwavelength based at least in part on a Raman effect in a waveguide, thelonger optical signal wavelength comprising a mid-infrared wavelength,at least a portion of the wavelength shifter comprising a ZBLANwaveguide, wherein the wavelength shifter further comprises: a firstreflector coupled to a first end of the ZBLAN waveguide; and a secondreflector coupled to a second end of the ZBLAN waveguide.